1. Field of the Invention
The present invention relates to an apparatus for monitoring hot waste water discharged from a power plant by using an airborne multispectral scanner system. More particularly, the present invention relates to an apparatus for monitoring hot waste water discharged from a power plant and the spread situation of the hot waste water by using an airborne multispectral scanner system.
2. Description of the Related Art
A thermoelectric power plant or a nuclear power plant has used a huge amount of river water or seawater to supply cooling water, and the cooling water is discharged in a hot state, so that the cooling water flows into a river or the sea at the outside the power plant.
Since the temperature of the discharged hot water is higher than water temperature of the surrounding river or surrounding sea, the discharged hot waste water exerts an influence on the inhabited environment of existing living things in the river or sea, and a civil complaint is continuously filed due to the discharged hot waste water.
Accordingly, the spread behavior of the hot waste water discharged from the power plant must be continuously monitored. In order to monitor the hot waste water, currently, an airborne multispectral scanner system has been used.
The airborne multispectral scanner system is mounted on a fixed wing aircraft (hereinafter, aircraft) to collect and analyze thermal energy, which is emitted from the hot waste water discharged from the power plant. The airborne multispectral scanner system can monitor a broad region through one flight.
The airborne multispectral scanner system is a device to obtain and analyze an infrared image. In order to clearly obtain the infrared image, the airborne multispectral scanner system uses an image obtaining sensor operating at an extremely low temperature.
In this case, the extremely low temperature refers to a temperature in which liquid-phase nitrogen is boiled, that is, refers to a temperature corresponding to a boiling point of the liquid-phase nitrogen
Recently, many devices have been developed to obtain the infrared image without the liquid-phase nitrogen. The devices are inferior to the existing airborne multispectral scanner system in terms of the resolution of the infrared image or the detection distance of the infrared image.
Accordingly, in order to obtain a precise image during the operation of the airborne multispectral scanner system, a device to cool an image obtaining sensor by using the liquid-phase nitrogen is essentially required.
As described above, the liquid-phase nitrogen is used to cool the airborne multispectral scanner system, and the airborne multispectral scanner system is cooled to about −200° C.
Therefore, the airborne multispectral scanner system must be basically provided with a tank to store liquid-phase nitrogen in order to cool the image obtaining sensor.
However, although the existing airborne multispectral scanner system is provided therein with the tank to store the liquid-phase nitrogen, since the capacity of the tank is excessively small, there is a limitation in tracking the spread behavior of the hot waste water discharged from the power plant for a long time.
For example, when the spread of the hot waste water of the power plant is preferably monitored, that is, when the spread situation of the hot waste water is preferably monitored for a sufficiently long time, that is, from a rising tide to a falling tide, or till a next rising tide or a next falling tide, the liquid-phase nitrogen is frequently completely depleted during the monitoring with the tank capacity of storing the existing liquid-phase nitrogen, so that it is impossible to monitor the spread situation of the hot waste water through one flight.
Furthermore, when taking into consideration a lost amount of liquid-phase nitrogen, which is naturally evaporated to reduce the pressure of nitrogen gas in an existing liquid-phase nitrogen storing tank, a great amount of liquid-phase nitrogen is wasted in the liquid-phase nitrogen storing tank.
In order to solve the above problem, in order to expand the capacity of the liquid-phase nitrogen storing tank embedded in the airborne multispectral scanner system, there has been suggested a scheme of providing a tank having a greater capacity by directly linking an auxiliary liquid-phase nitrogen tank with the liquid-phase nitrogen storing tank. According to the above scheme, when liquid-phase nitrogen contained in the auxiliary liquid-phase nitrogen tank is introduced into the liquid-phase nitrogen contained in the liquid-phase nitrogen storing tank, the liquid-phase nitrogens may be exploded during the mixing between the liquid-phase nitrogens. Accordingly, the above scheme is not determined as being a preferable scheme.
Meanwhile, the related art is disclosed in U.S. Pat. No. 4,626,063 (issued on Dec. 2, 1986).